Exploration of the Chicken Adipose Tissue

Adipose tissue is essential for lipid storage and thus, energy regulation and maintenance. Many organs in the body utilize lipids as their primary energy source, such as the heart. In addition, when glucose supplies are insufficient adipose tissue is broken down and fats are utilized systemically as a primary energy source. This is regulated by the endocrine system primarily through the regulation of glucagon and insulin. Adipose tissue is also involved with the immune system particularly in eliciting an inflammatory response through cytokine signaling and the release of interleukins. Chickens have two major fat pads: an abdominal fat pad and a cardiac fat pad. The abdominal fat pad is located on the ventral side, above the GI tract. The cardiac fat pad is situated on the atria of the heart and surrounds the aorta. These fat pads are different in coloration and size which leads to the hypothesis that these fat pads have different functions. The objectives of the project are to (a) identify genes that are unique to each type of adipose tissue when compared to the rest of the body, through the collection of other tissues and (b) to identify genes that are differentially expressed in each type of adipose tissue in comparison to each other to better understand the functioning of these fat pads in the chicken and the pathways that they are involved in at the transcriptomic level. Overall design: Male Ross 708 broiler chickens were raised from day of hatch to day 42, typical market age, on the University of Delaware farm. Birds were placed into a house. The house was kept at 23 hours of light and 1 hour of dark and birds were placed on litter and given feed (meeting all NRC requirements) and water with ad libitum access. The house was kept at 35 degrees celsius for the first week and the temperature was decreased 5 degrees celsius each week until 25 degrees celsius. The house was maintained at 25 degrees celsius for the remainder of the study. Necropsies were performed at several points throughout the trial (days 21, 22, 26, 32, and 42).

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